Clock control mechanism



Aug. 24, 1948. H. N. DEANE CLOCK CONTROL MECHANISM Filed 001;. '7, 1944I INVENTOR. flfnfyfi Deqne.

Patented Aug. 24, 1948 CLOCK CONTROL DIECHANISM Henry N. Deane,

Gardner, Mass, assignor to Simplex Time Recorder 00., Gardner, Mass, acorporation of Massachusetts Application October 7, 1944, Serial No.557,651

3 Claims. 1

This invention relates to time clocks operated by synchronous motors andrelates more particularly to mechanism for resetting secondary clocks ofthis type to indicate the exact time shown by a master or control clock.The invention also relates to mechanism adapted to reset both the masterclock and the secondary clocks after a general current interruption.

To the attainment of these general objects, I have provided. certaincontrol mechanism of simple and effective construction and which isexceptionally well adapted to its intended purposes.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claims.

A preferred form of the invention is shown in the drawing which is adiagrammatic view illustrating my improved control mechanism.

Referring to the drawing, I have shown a master or control clock C, andtwo secondary clocks Cl and C2. While two clocks only are shown in thedrawing, it will be understood that any desired number of additionalsecondary clocks -may be placed in parallel with the clocks Cl and C2.

The master clock C is indicated as having a drive shaft It provided witha ratchet wheel H intermittently advanced by a feed pawl 12 on a feedlever Hi. The lever M has a stud l engaged by a cam 15 on a drive shaftH. A lowspeed synchronous motor M and a high-speed synchronous motor Mare connected to the cam shaft ll through differential gearing of anyusual type enclosed in a casing H3. The cam shaft It may thus be drivenat low speed by the motor M, at high speed by the motor M, or at a stillhigher speed by the combined action of both motors M and M.

The motor M is commonly designed to turn the cam shaft I! one revolutionper minute so that the sixty-tooth ratchet wheel I l is advanced onetooth for each minute and thus makes one revolution each hour.

Each secondary clock CI and C2 is similarly provided with a drive shaft26 and ratchet wheel 22 and with a slow-speed motor 22, a high speedmotor 23, and a differential gear box 24.

The control clock C has a pair of contacts 39 which are normally openbut which close when a spring blade 32 drops into a notch 33 in a disc34 mounted on and rotatable with the shaft [0. A second pair of contacts46 in the clock C are normally closed but open when a blade 42 dropsinto a notch 43 in a disc 44, also mounted on the shaft I 9.

Similarly, each secondary clock Cl and C2 is provided with a pair ofcontacts 5!] which are normally closed but which open when a blade 52drops into a notch 53 in a disc 56% mounted on its shaft 20.

A three-pole double-throw switch 5 is maintained normally in the raisedposition shown in the drawing by a spring 55, but is shifted to loweredposition by a solenoid plunger 55 when its solenoid 57 is energized.Power is supplied through line wires L and L and the system becomesoperative on the closing of a master hand switch 60.

The line wire L is then connected through the switch 50 to the upperblade SI of the switch S and thence through upper contact 62, wire 63and branch wires 64 to one terminal of the slowspeed motor 22 in eachsecondary clock. The return circuit is through branch wires 65 and areturn wire 66 to the line wire L. The motors of the secondary clocksare thus continuously energized and the clocks are regularly advanced atminute intervals.

At the same time the line wire L is connected through wire 70 and branchwire 1 I to the slowspeed motor M of the control clock C. A branch wire12 and return wire 13 completes the return to the line wire L, thuscontinuously rotating the motor M and advancing the control clock atminute intervals through the feed mechanism previously described.

The discs 34 and 44 on the drive shaft I!) are {so set that thenormally-open contacts 33 will be closed when the clock C is advanced tothe fiftyninth minute, and the normally-closed contacts 1B will beopened when the clock C is advanced to the sixtieth minute. Similarly,the control discs 54 on the secondary shafts 2!) are set so that thenormally-closed contacts 58 will be opened when the secondary clocksreach the sixtieth minute.

The notches 33, 43 and 53 in the control discs are of such angularextent that the normallyopen contacts 30 remain closed for a minuteinterval only, and the normally-closed contacts 433 and 50 remain openfor a minute interval only.

- The contacts 40 and 5!] close as soon as the secondary clocks areadvanced to the first minute.

The operation for time-correction is as follows: At the fifty-ninthminute, the blade 32 drops into the notch 33 of the disc 44 and thecontacts 30 close. The line wire L is then connected through wire 10 andits extension 14 to the upper 3 contact point 3!], and thence throughlower contact point 30, wire 15 and branch wire 16 to the solenoid coil51 which operates the triple pole switch S. The circuit is completedthrough branch wire 11 and return wire 1-3 to the line wire L.

The plunger 56 is thus actuated to shift the three blades of the switchS downward to engage the lower contacts, and in particular to engage themiddle blade 80 with its lower contact 8| which is connected by a branchwire 82 to the wire 15 previously described.

As the contacts 30 are at this time closed, the circuit is now completefrom the line wire L through wires in and 14, contacts 30, wires 15 and82, contact 8i and switch blade 80 to a wire 83 which is connected bybranch wires 84 and normally-closed contacts 50 to wires 85 leading toone terminal of each high-speed motor 23. The return circuit iscompleted to the line wire L through branch wires 86 and through returnwires 65 and 66 previously described.

The high-speed motors 23 will thus start in operation at the fifty-ninthminute and will continue to turn the associated cam shafts at their highspeed of ten revolutions per minute until the secondary clocks havereached the sixtieth minute, when the contacts Eli-will separate and thehigh-speed motors will stop. It will also be noted that the low-speedmotors 22 were previously stopped when the solenoid 5'! was energizedand the switch blade 6| was moved downward away from its upper contact62. Consequently the secondary clocks will now be stopped at thesixtieth minute, which time will be indicated by each secondary clock.

As soon as the control clock C advances to the sixty minute position,the blade 32 will be raised, the contacts (ill will be opened, thesolenoid 51 will be deenergized, and the spring 55 will restore thethree blades of the switch S to raised position. All parts are thusbrought back to their original or normal running position, and thelow-speed motors 22 of the secondary clocks are again started inoperation.

I have thus provided simple and efficient mechanism for advancing thesecondary clocks to show the correct time of the control clock at hourlyintervals, if for any reason one'or more of the secondary clocks hasbeen delayed and has gotten out of step with the control clock.

It sometimes happens, however, that an interruption of current in theline wires L and L will throw the control clock as well as the secondaryclocks out of correct time. It is customary to provide a reset unit totake care of such current interruption in a synchronous system. I haveindicated a reset device It for this purpose, the specific constructionof said device forming no part of my present invention. For presentpurposes, it may be assumed that the device R comprises a spring-drivenor battery-driven clock unit which will operate during the currentinterruption and which will store up the interval of delay until currentis again supplied.

When this happens, a circuit will be completed from line wire L throughthe reset device R to terminals 90 and 9| connected thereto.

The terminal 90 is connected through a wire 22 to the upper contact 93of the middle switch blade 80, and thence through wire 83, branch wires32, contacts 50 and wires 85 to the high-speed motors 23 in thesecondary clocks, the return being through the branch wires 86 andreturn wires 65 and 66 to the line wire L.

the end of the At the same time the terminal BI is connected through thelower switch blade 94 to its upper contact 95 and thence through wire96, contacts 40 and wire M to the high-speed motor M in the controlclock C, the circuit being completed through wires 91 and 13 to the linewire L. The high-speed motors 23 and M are thus all set in operation toadvance the clocks for the period of delay stored by the reset device R.

During this resetting period, the low-speed motors M and 22 are alsooperative, as the blade 6 I is in normal or raised position. When thedelay has been corrected, the reset device R cuts out and normaloperation only is continued.

It is desirable to suspend the operation of the reset device R for theperiod of two minutes at hour when the ordinary correcting of thesecondary clocks takes place, and for this purpose the contacts 40 areprovided.

Assuming that the reset device is in operation and with all of thelow-speed and highspeed motors active, the blade 32 at the fiftyninthminute will drop into the notch 33. of the disc 34 in th control clockC, thus closing the contacts 30. This will energize the solenoid 51which will shift the triple blades of the switch S downward, thusbreaking the circuits through which the low-speed motors 22 and thehigh-speed motors M and 23 had been operated by the reset device R. Atthe same time, the middle blade 83 engages its contact 8! and operatesthe high speed motors 23. as usual for time correction. This continuesuntil the secondary clocks reach the sixtieth minute, when the contacts50 open to stop the high-speed motors 23. When the control clock reachesthe sixtieth minute, the contacts 313 are opened to deenergize thesolenoid 5i and to restore the reset circuits. But at the same time theblade 42 drops into the notch A3 in the disc 44, opening the contacts 40and breaking the circuit through the high-speed motor M for the controlclock C. The open contacts 52 already hold the high-speed secondarymotors inoperative. The low-speed motors M and 22 are now in operationand at the end of the sixtieth minute the contacts M) will close,restoring the motor M to control by the reset device R, and the contacts50 will close, restoring the high-speed secondary motors 23 to controlby the reset device.

The reset device It then keeps all high-speed and low-speed motors inoperation until the stored delay period has been made up. The resetdevice then cuts out, leaving the low-speed motors M and 22 only innormal operation.

In the specification and claims, the reference to fifty-ninth, sixtiethand first minutes is illustrative only to identify successive timeintervals, and the corrective apparatus may obviously be arranged tooperate at any other successive inter vals in the hour period.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

1. A synchronous clock system comprising a control clock, a plurality ofsecondary clocks, a normally-operating low-speed motor and anormally-inoperative high-speed motor effective to drive each secondaryclock, a normally-operating low-speed motor and a normally-inoperativehigh-speed motor eflective todrive the control clock, differentialconnections between the lowspeed and high-speed motors in each clock,means in said control clock to render the low-speed motors in thesecondary clocks inoperative and the associated high speed motorsoperative just prior to a selected time in each hour for the purpose ofcorrecting the time shown by each secondary clock, means in eachsecondary clock to stop said high-speed motors when each secondary clockhas advanced to indicate said selected time, means in said control clockto start said lowspeed motors in said secondary clocks when said controlclock thereafter indicates the selected time, a reset device elfectiveto render the highspeed motors in both the control and the secondaryclocks all operative to drive said clocks at above normal speed after acurrent interruption and until the stored interruption interval has beenmade up in said control clock and in said secondary clocks by saidhigh-speed motors, and means to cause the low-speed motors in all ofsaid clocks to operate simultaneously and cumulatively with saidhigh-speed motors during resetting and under the control of said resetdevice.

2. In a clock system supplied from an alternating current source, amaster clock and a secondary clock, said clocks havin normal rateself-starting synchronous driving motors normally energized from suchsource, and self-starting synchronous resetting driving motors which arenormally deenergized but arranged when energized from said source todrive their clocks at several times normal rate, energizing circuits forboth secondary clock motors under control of the master clock includingsynchronizing switch means operated periodically by the master clock andeffective during a short clock synchronizing interval just prior to thearrival of said clock at a predetermined time indication and becomingineifective upon such arrival for opening the circuit of the normal ratemotor of the secondary clock and closing the circuit of the resettingmotor of the secondary clock, switching means operated by the secondaryclock and effective only when said secondary clock is at saidpredetermined time indication for opening the circuit of its resettingmotor, and energizing connections to both resetting motors whichconnections are independent of the aforesaid master clock synchronizingswitch means, said last-mentioned energizing connections includingnormally closed switching means opened by said master clock during theclock synchronizing interval thereof, and normally open switch means insaid energizing when it is deconnections adapted to be closed sired toreset both of said clocks.

3. A clock system comprising in combination with a source of alternatingcurrent supply, a master clock and a plurality of secondary clocks, eachclock containing a pair of self-starting synchronous motors, one acorrect rate motor for normally driving its clock at time keeping rateand the other a resetting motor for driving its lClOCk at several timescorrect rate for resetting purposes, circuit connections whereby saidmotors may be connected to and energized from said source of supply, thecorrect rate motors being normally connected to said source and theresetting motors being normally disconnected from said source, clolcksynchronizing circuit control means for synchronizing the clocks at apredetermined time indicating synchronizing position comprising anormally open switch in the energizing circuit to all of the secondaryclock resetting motors closed by the master clock during periodicsynchronizing intervals, a normally closed switch in the energizingcircuit to all of the secondary clock correct rate motors opened by themaster clock during such synchronizing intervals and normally closedswitches in the energizing circuits of the resetting motors of theindividual secondary clocks opened by such clocks when they arrive atsaid predetermined synchronizing position, and clock resetting controlmeans comprising a normally open resetting switch in the energizingcircuit to all of the resetting motors in both master and secondaryclocks adapted to be closed when it is desired to reset all of saidclocks, said resetting circuit being independent of the aforesaidnormally open switch controlled by the master clock but in seriesrelation with the aforesaid normally closed switches in the secondaryclocks, and means operated by said master clock for opening saidresetting circuit during clock synchronizing intervals.

HENRY N. DEANE.

REFERENCES CITED The following references are of record in the

